The present disclosure relates to a TFT array driving technology for a thin film transistor (TFT) display panel, and to a gate driver for providing a gate drive signal for a TFT array substrate, and more particularly to a gate driver capable of outputting a gate drive signal having an adjustable driving capability, a configuration system and a configuration method for configuring a plurality of gate drivers to equalize the driving capabilities among them.
In a thin film transistor liquid crystal display (TFT-LCD), it is necessary to use a gate driver to drive and control the TFT array. As the resolution of the TFT-LCD becomes higher, the number of gate drivers needed increases. Different gate drivers drive and control the different TFT array regions of the display panel. Similarly, the same gate driver also has different fan-out ends to drive different fan-out sub-regions of the TFT array region corresponding to the gate driver.
Different gate drivers are arranged at different locations of the display panel, and thus the wirings or routings from the outputs of the gate drivers at different locations to the corresponding TFT array region (e.g., the wirings on the glass substrate between the gate drivers and the TFT array regions) are different from each other. For example, different lengths lead to different impedances. That is to say, the difference between the external wirings of the different gate drivers results in a difference between the drive control signals which are finally reflected in the TFT array regions. This difference is mainly reflected in the difference between the rising times of the drive control signals in the form of voltage pulse signal. That is, the rising times taken from the low level (VGL) to the high level (VGH) are different from each other. In the gate driving signals or the driving control signals of their corresponding TFT array regions, the time difference from VGL to VGH mainly affects their corresponding driving capabilities.
In view of the above problems, the present disclosure provides the following technical solutions.
According to an aspect, an embodiment of the present disclosure proposes a gate driver for providing a gate drive signal for a thin film transistor array substrate, the gate driver comprising: a driving capability detection module configured to detect a driving capability of the gate drive signal and output a detection signal of the driving capability; and a driving capability adjustment module configured to adjust the driving capability of the gate drive signal based on the detection signal of the driving capability.
In some embodiments, the driving capability detection module is configured to receive at least a feedback signal collected from the gate drive signal and to detect the driving capability of the gate drive signal based at least on the feedback signal, the driving capability being represented by a rising time from low level to high level of the gate drive signal in the form of voltage pulse signal.
In some embodiments, the driving capability adjustment module is configured to adjust the driving capability of the gate drive signal based on an adjustment instruction generated based on the detection signal and configured and input from outside.
In some embodiments, the driving capability detection module comprises: a comparator configured to have a first input end input with a reference voltage signal and a second input end input with the feedback signal collected from the gate drive signal, wherein the comparator compares the feedback signal with the reference voltage signal to determine whether the gate drive signal has risen from a low level to the reference voltage; and a timing sub-module for determining the time period taken by the gate drive signal to rise from the low level to the reference voltage and outputting the detection signal based on the time period.
In some embodiments, the timing sub-module comprises a counter which counts the time period taken by the gate drive signal to rise from the low level to the reference voltage using a standard clock signal and outputs a count value.
In some embodiments, the driving capability detection module comprises a reference voltage signal providing sub-module comprising a first resistor and a second resistor arranged in series, the first input end of the comparison sub-module being electrically connected to a node between the first resistor and the second resistor.
In some embodiments, the reference voltage signal providing sub-module is configured as a signal source generating the gate drive signal.
In some embodiments, the driving capability adjustment module comprises: a driving capability adjustment component provided in a push-pull output circuit of the gate driver, and a register for configurably storage of the adjustment instruction which is a digital signal; wherein the driving capability adjustment component is adjusted and controlled by the adjustment instruction in the register.
In some embodiments, the driving capability adjustment component is a digital potentiometer or a digital capacitor, or a circuit formed by a digital potentiometer or a digital capacitor.
In some embodiments, the push-pull output circuit comprises a first MOS transistor and a second MOS transistor arranged in series; the first MOS transistor is connected to a signal source having a high level, and the second MOS transistor is connected to a signal source having a low level, and the driving capability adjusting component is provided in series between the first MOS transistor and the second MOS transistor; wherein the feedback signal is collected at a node between the second MOS transistor in the push-pull output circuit and the driving capability adjusting component.
In some embodiments, the detection signal is a digital signal.
According to another aspect, an embodiment of the present disclosure provides a configuration system for configuring driving capabilities of a plurality of gate drivers as described above, the various gate drivers being used for driving different thin film transistor array regions of a thin film transistor array substrate respectively, the configuration system comprising:
a plurality of gate drivers as described above;
a controller for storing said detection signals output from the plurality of gate drivers and comparing the respective detection signals corresponding to the plurality of gate drivers respectively to output different adjustment instructions corresponding to the various gate drivers, such that the driving capabilities of the various drive control signals obtained after the gate drive signals are output from the various gate drivers to the respective thin film transistor array regions are relatively consistent.
In some embodiments, the plurality of gate drivers are provided on a same thin film transistor array substrate.
In some embodiments, the controller is configured with a driving capability configuration rule and outputs the adjustment instructions based on a comparison result between the configuration rule and the detection signals.
In some embodiments, the driving capability configuration rule is set according to the driving capability differences between the gate drive signals output by the plurality of gate drivers and/or the external wiring conditions corresponding to the plurality of gate drivers.
In some embodiments, the detection signal is output through an external pin of the gate driver and is transmitted to the controller via an I2C communication line external to the gate driver.
According to another aspect, an embodiment of the present disclosure provides a method of configuring driving capabilities of a plurality of gate drivers, comprising the steps of:
receiving feedback signals collected from the gate drive signals output from the plurality of gate drivers;
detecting driving capabilities of the gate driving signals based on the feedback signals, and outputting detection signals that reflect the driving capabilities of the gate driving signals;
comparing the respective detection signals corresponding to the plurality of gate drivers to output different adjustment instructions corresponding to the different gate drivers, respectively,
adjusting the driving capabilities of the gate drive signals in accordance with the adjustment instructions such that the driving capabilities of the various drive control signals obtained after the gate drive signals are output from the various gate drivers to the respective thin film transistor array regions are relatively consistent.
In some embodiments, the method further comprises driving the same thin film array substrate with the output signals of the plurality of gate drivers after adjusted and configured.
In some embodiments, the adjustment instruction is generated based on a comparison result between a pre-set driving capability configuration rule and the detection signal.
In some embodiments, the driving capability configuration rule is set according to the driving capability difference between the gate drive signals output by the plurality of gate drivers and/or the external wiring conditions corresponding to the plurality of gate drivers.
The driving capability of the gate driver of the present disclosure can be detected and become adjustable so that after adjustment by the configuration system of the present disclosure, the drive control signals received by the different TFT array regions corresponding to the plurality of gate drivers respectively have uniform driving capabilities, which can avoid the phenomenon of splitting-screen.
The above and other objects and advantages of the present disclosure will become more complete and apparent from the following detailed description made in conjunction with the accompanying drawings in which like or similar elements are denoted by like reference numerals.
Some of multiple of possible embodiments of the present disclosure are described below, which are intended to provide a basic understanding of the present disclosure and are not intended to identify the key or determinative elements of the invention or to define a protection scope. It will be readily understood that other implementations which can replace each other may be proposed by those ordinary skilled in the art without departing from the spirit of the invention, in accordance with the technical solution of the present disclosure. Accordingly, the following detailed implementations and accompanying drawings are only illustrative of the technical solutions of the present disclosure and should not be construed as the whole invention or as definitions or limitations of technical solutions of the present invention.
In the present context, the “gate drive signal” refers to a signal directly output by the gate driver for driving the TFT array region, which has not been transmitted by external wiring or routing, and the “drive control signal” refers to a signal received by the TFT array area, which is a signal become by the gate drive signal after passing through the wiring between the gate driver and the TFT array region.
Herein, the driving capability of the gate drive signal or the drive control signal is represented by the rise time taken by the signal changing from the low level VGL to the high level VGH, and can also be understood as the VGH rising speed.
Thus, for different TFT array regions, the driving capabilities of the received drive control signals are either unbalanced or inconsistent, i.e., the time periods taken by the drive control signals to rise from VGL to VGH are different; this unbalance results in a “splitting-screen” phenomenon arising during display (e.g. arising in a reliability test of the display panel under low temperature etc.).
Of course, due to the difference between the different gate drivers by themselves, the driving capabilities of the gate drive signals output by them are different by themselves. For example, even though a same type of chip produced by a same manufacturer is used, due to fluctuations in the process of semiconductor manufacturing and other reasons, the driving capabilities of the gate drive signal output by them are more or less different. If the driving capability difference of gate drive signals is ultimately reflected in the drive control signals finally received by the TFT array regions, the above splitting-screen phenomenon is generated due to the unbalanced driving capabilities.
As shown in
Still as shown in
In this embodiment, before the gate driver 20 leaves the factory, a register 221 of each gate driver 20 is configured with a corresponding adjustment instruction so that a plurality of gate drive signals output from the plurality of gate drivers 20 are operably configured, until the TFT array substrate driven by the plurality of the gate drivers 20 does not exhibit a splitting-screen phenomenon substantially during display operation (e.g., under low temperature and other reliability test conditions).
It should be noted that, in other embodiments, a digital capacitor may be used to replace the digital potentiometer 222 to realize the function of the driving capability adjustment component, and the function of the driving capability adjustment component may be realized by a circuit formed by a digital potentiometer or a digital capacitor.
Still as shown in
The comparator 211 compares the feedback signal 2331 with the reference voltage signal to determine whether or not the gate drive signal as the feedback signal 2331 has successfully risen from the low level to the reference voltage. The comparator 211 outputs a comparison output signal 219 (for example, a high level) at the moment of the feedback signal 2331 rising from the low level to the reference voltage, and the comparison output signal 219 is sent to a counter 240 in the driving capability detection module 210 which is used for timing sub-module. The counter 240 counts the standard clock signal under the control of the comparison output signal 219 and starts to count from the time point when the gate drive signal starts rising from the VGL until the time point at which the comparison output signal 219 is received, and then the count result is obtained and the signal 249 is output. The output count result reflects the rising time of the gate drive signal from VGL to VGH, i.e., reflects its driving capability, so that the driving capability detection module 210 realizes real-time detection of the driving capability of the gate drive signal currently outputted by the gate driver 20, with the signal 249 as the detection signal.
The driving capability detection principle described above is explained by an example of the gate drive signal 90 shown in
The timing sub-module may include a clock module for providing the standard clock signal, which module may be embodied by a crystal oscillator within a chip. It will be understood that the standard clock and reference voltage must have sufficient stability as much as possible to avoid errors due to fluctuations, that is, to facilitate improving the detection accuracy for the driving capability.
Still as shown in
In particular, the gate driver 20 may be specifically implemented by an IC, and at least the driving capability detection module 210 and the driving capability adjustment module 220 described above are integrated within the IC. The other components included in the gate driver 20 are for example achievable and well known by those skilled in the art and are not specifically described herein.
As shown in
It should be noted that the above configuration process may be performed under a reliability test condition such as a low temperature, and the gate drive signals 90 outputted from the gate drivers 201, 202 to 20i are output to the corresponding TFT array regions through external wirings on the TFT array substrate. It is possible to determine whether or not the gate drivers 201, 202 to 20i have been successfully adjusted by judging whether or not the display effect of the display panel has a splitting-screen phenomenon.
The below are described with configuring three gate drivers 201, 202, and 203 as an example.
The equalization of the above drive control signals 90′, 91′, 92′ is achieved by compensating for the different delays of the external wiring to the gate drive signals 90, 91, 92. Thus, based on the disclosure of this principle, those skilled in the art can specifically set the above-described driving capability configuration rule in accordance with the different external wiring conditions of the gate drive controllers.
The above example are described in case that the initial gate drive signals outputted by the three gate drivers 201, 202, and 203 are identical, and the delays caused by the external wirings to which they correspond respectively are different from each other. Hereinafter, the way of configuring the gate drivers 201, 202, and 203 are further illustrated in the case that the gate drive signals outputted from the three gate drivers 201, 202, and 203 are different and the delays caused by the external wirings to which they correspond respectively are same with each other.
As shown in both
It should be noted that the difference in driving capabilities of the gate drive signal output from the above-mentioned gate drivers 201, 202 and 203 can be caused by various factors such as unequal driving capabilities due to accuracy fluctuation of the manufacturing process of the gate driver.
Therefore, the setting of the driving capability configuration rule in the controller 250 can be actively set according to the specific actual situation. For example, if the initial driving capabilities of the plurality of gate drivers are the same, the driving capability configuration rule is set according to the external wiring conditions; and if the external wiring conditions to which the plurality of gate drivers correspond are the same, the driving capability configuration rule described above is set according to the driving capability difference of the gate drive signals output by the plurality of gate drivers. Of course, it will be understood that if there is a difference in the driving capability between the plurality of gate drivers and the external wiring conditions are not coincident, the driving capability configuration rule is set according to both the driving capability difference of the gate drive signals output from the plurality of gate drivers and the external wiring conditions to which the plurality of gate drivers correspond. For those skilled in the art, according to the above teachings or disclosures, it is entirely possible that the driving capability difference of the gate drive signals output from the plurality of gate drivers and the external wiring conditions corresponding to the plurality of gate drivers (in the case of the mounting positions thereof being determined) can be determined. Therefore, despite the driving capabilities of the drive control signals received by the different TFT array regions are not equalized for any reason, the driving capabilities of the drive control signals can be equalized by the above configuration process, thereby eliminating the splitting-screen phenomenon.
Preferably, the above configuration process may be performed prior to the mass production of the display panel, and without considering the difference between the gate drivers themselves, after determining adjustment instructions for the gate driver at the respective positions, the corresponding adjustment instructions can be directly configured in the registers of the gate drivers at the respective positions.
It will be appreciated that when the component is “connected” or “coupled” to another component, it may be directly connected or coupled to another component or there may be intermediate components between it and another component.
The above example mainly describes the drive controller, the configuration system, and the configuration method thereof of the present disclosure. While only some of the embodiments of the present invention have been described, it will be understood by those of ordinary skill in the art that the invention may be embodied in many other forms without departing from the spirit and scope thereof, for example, the corresponding adjustment instructions are configured and stored by the use of other storage device similar to the registers 221. Accordingly, the illustrated examples and embodiments are to be considered as illustrative and not restrictive, and that the invention may include various modifications and replacements without departing from the spirit and scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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201510670568.9 | Oct 2015 | CN | national |
The present application is the U.S. national phase entry of PCT/CN2016/100306, with an international filing date of Sep. 27, 2016, which claims the benefit of Chinese Patent Application No. 201510670568.9, filed on Oct. 16, 2015, the entire disclosures of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2016/100306 | 9/27/2016 | WO | 00 |